Various control methods of this type and control apparatuses are known from the prior art.
U.S. Pat. No. 5,261,858 discloses an automatic control method for a bicycle gear shift that provides adjustable hysteresis. This hysteresis is used to ensure that changing back and forth between individual gears does not occur too often. When the bicycle is changed into a new gear, the computer determines a desired wheel speed and an upward change wheel speed and a downward change wheel speed for the new gear. The desired wheel speed is achieved when the pedals of the bicycle are operated at the desired pedalling frequency in the new gear. The upward change wheel speed refers to the wheel speed at which the computer automatically changes into a higher gear, and the downward change wheel speed refers to the wheel speed at which the computer automatically changes into a lower gear. The upward change wheel speed is set such that it is greater than the current wheel speed, and the downward change speed is set so that it is lower than the current wheel speed. The setting of these upward change and downward change wheel speeds results in a hysteresis effect. When the current wheel speed exceeds or falls below the upward change wheel speed or the downward change wheel speed respectively, the computer generates an upward change signal or a downward change signal if the crank and hub arrangements are suitably positioned. According to U.S. Pat. No. 5,261,858 the computer can adjust the upward change or downward change wheel speed in particular situations in order to ensure a steady pedalling frequency.
EP 0 899 188 B1 discloses a method for automatic gear-changing in a gear mechanism of a bicycle through a gear control in accordance with a determined speed of the bicycle. According to EP 0 899 188 B1 different bicycle speeds are stored in a first speed table, in a second speed table, in a third speed table and in a fourth speed table. A decision is taken as to whether to change between individual gears with reference to the bicycle speeds stored in the speed tables.
U.S. Pat. No. 5,059,158 discloses an electronic control system for a gear of a bicycle. The system calculates continuously, in a fully automatic operating system, the theoretical cadence (pedalling frequency) of the rider for the current gear ratio and the current bicycle speed. The system then determines whether the calculated cadence lies within the limits chosen by the rider. If the calculated cadence is too low, the system informs the rider through audible or visible signals, and then automatically changes into the next lower gear in order to increase the rider's cadence. If, conversely, the calculated cadence is too high, the system informs the rider through audible or visible signals, and then automatically changes into the next higher gear in order to decrease the rider's cadence. The system maintains the rider's cadence within preset limits for all gear ratios and bicycle speeds.
WO 02/055373 A2 furthermore discloses an automatic gear system for a bicycle.
It is an object of the present invention to provide a method for controlling automatic gear-changing processes of an electric gear-change apparatus with which the riding comfort of a bicycle rider when using an automated gear-change apparatus can be further improved.